Pneumatic piano-player action.



J. POSPISIL.

PNEUMATIC PIANO PLAYER ACTION.

APPLICATION FILED OCT. 16. 1915.

v T a- Ill/lzk INVENTOR 7. Pas 0. 6. 1

A HOME Y8 Patented Oct. 31, 1916.

J. POSPISIL.

v PNEUMATIC PIANO PLAYER ACTION. 1 7

APPLICATION FILED OCT-16.1915. v 1,203,401. v Patented Oct. 31,1916.

3 SHEETS'SHEET 2- WITNESSES INVENTOR J Pas 016M V A BY M 49 ATTORNEYS J. POSPISIL.

PNEUMATIC PIANO PLAYER ACTION.

APPLICATION FILED OCT. 16, 1915.

1,203,401. Patented Oct. 31,1916.

'3 SHEETs -SHEET 3.

4/ 3/ 30 3/ a2 V 22- Z 40 g "if 46 A A Wm] M 1 S Win; ilm mlll 5/ INVENTOH, J [61/ WITNESSES A TTORIVEYS JOSEPH POSPISIII, OI NEW JERSEY.

mmnc PIANO-PLAYER ACTION.

Specification of Letters Iatent.

Patented Oct. 31, 1916.

Application fled October 18, 1915. Serial No. 56,241.

To all whom it may concern:

Be it known that I, JOSEPH POSPISIL, a citizen of the United States, and a resident of Newark, in the county of Essex and State of, New Jersey, have invented a new and Improved Pneumatic Piano-Player Acmcatmg with bellows 19 or other suitable tion, of which the following is a full, clear,

and exact description.

This invention relates to musical instruments and has particular reference to pneumatic actions for pianos, organs or the like.

Among the objects of the invention is to provide a construction involving metallic air chests of sheet metal or the equivalent thereof, whereby the danger of leakage of air due to shrinkage, warping or the like, incident to instruments as ordinarily made, is avoided.

A further object of the invention is to improve the mechanism of pneumatic action apparatus whereby, even though metallic parts be used, there is. no objectionable harshness of tone resultin A still further object o the invention is to reduce the requirement for frequent repairs in pneumatics, but providing a means whereby repairs may be readily made when necessary at slight cost or inconvenience.

With the foregoing and other objects in view, the invention consists in the arrangement and combination of parts hereinafter described and claimed, and while the invention is not restricted to the exact details of construction disclosed herein, still for the purpose of illustrating a practical embodiment thereof reference is had to the accompany drawings, in which like reference characters designate corresponding parts in the several views, and in which Figure 1 is a fragmentary vertical transverse section of a pneumatic player piano showing my inprovements; Fig. 2 is a vertical longitudinal section of the same, parts being broken away to save space; Fig. 3 is a vertical sectional view of one of the val've; casings; Fig. 4 is a plan view of the same; Fig. 5 is a vertical longitudinal section ofzjoneof the air tube couplings; and Fig. 6 is ,a-vertical sectional detail of the front wall ofoneyo'fqthe air trunks indicating the gasket construction for the valve casing connection! Referring now more particularly to the drawings, I show a piano casing 10 having a sounding board 11, strings 12, hammers I '13,-and keys: 14, all of any well known or suitable design or construction. At the front portion of the casing is arranged a tracker bar 15 over which the music sheet I 16 operates from one roller 17 to another as heretofore.

At 18 is indicated a vacuum chest commuform of air pump for the purpose of maintaining a suitable degree of tension or vacuum within the chest 18.

In pneumatic instruments as heretofore ordinarily made, the several pneumatics are connected independently to the air trunk or trunks, the connection between the same and the vacuum chest '18 being had at a single point or portion of the vacuum chest with the result that the vacuum pressure operates at different parts of the keyboard with varying degrees of force. To overcome this objection I provide connections between the vacuum chest and the air trunks at a plurality of different places. The condition of air pressure in the vacuum chest is uniform throughout its length, and even though the air trunks may be very small in cross section, by retaining the connection between the same and the vacuum chest at different points, there is no perceptible variation in force at different parts of the keyboard. As heretofore, the several hammer actions are connected to independent pneumatics 19 and each pneumatic has a tubular connection 20 through a. rubber or similar coupling 21 with the upper portion of a valve casing 22. The rubber coupling 21 receives directly a smooth-ended nipple 23. The several valve casings 22 are detachably connected to a series of three air trunks 24: extending horizontally across the instrument from one end to the other parallel to one another. Except for the nipple connections with the valve casings described below, these air trunks are airtight and are preferably constructed of sheet metal or the equivalent, rendering the same solid with respect to shrinkage, Warping or other conditions tending to cause leakage of air. A

series of tubes 25 lead from each end of the forth briefly by way of a full understanding the novel features of construction as follows: Each pneumatic comprises relatively fixed and movable parts connected by an accordion web and the movable part normally depends by gravity with the pneumatic filled with air under normal pressure. The vacuum mechanism and the valve mechanism 22 serve to provide means for exhausting the air from the attached pneumatic for a time corresponding to the length of the note being played, the exhaustion of the air from the pneumatic causing the connected hammer to strike.

Each valve casing 22 for the sake of durability and reliability of action is preferably made of metal, vulcanized rubber or some other cheap reliable material. Each of such casings is shown of substantially cylindrical form having'a vertical axis. The main casing comprises an upper part or cap 27 into which is tapped a valve drum 28 serving as a coupling for the base portion 29 of the casing. The top of the casing is closed but for a central guide hole 30, and a series of openings 31 surrounding the same. Within the top of the casing and surrounding the openings just described is a valve seat 32 below which and spaced therefrom is normally located a valve 33 resting upon an upwardly projecting valve seat 34 surrounding the series of openings 35 in the partition or valve drum. The valve drum 28 serves not only as a coupling for the u per and lower portions of the valve casing 27 but constitutes also at its lower end a holder for a diaphragm 36 having its periphery glued or otherwise secured to the lower edge of the valve drum and clamped in such position-byv the base screwing thereagainst. The upper portion of the valve casing and the valve drum therein are locked in fixed relative position by means of a nipple 37 tapped through one side of the same just below and parallel to the nipple 23. The diaphragm 36 carries at its center a rigid seat 38 upon which the valve stem 39 rests, the weight of the valve 33 suflic-ing to maintain it seated upon the valve seat 34 under normal conditions. The valve 33 comprises a pair of disks 40 formed of leather or its equivalent. Midway between the disks 40 is a metal disk 41 and between the metal disk and each of the leather disks is a felt cushion 42. All of these parts are secured upon the valve stem 39 by means of col-.

lars 43.

The 'base29 of the valve casing is provided with a central port 44 communicating directly with the bottom surface of the diaphragm' 36 and communicating at its lower end with the bore 45 of an air tube 46. The

front end of the tube 46 is bent preferably upwardly just in front of the valve casing. The rear end of the tube 46 extends rearwardly forming a nipple 46 of about the same length as the nipple 37. The two nipples 37 and 46 are fitted into the front wall of one of the air trunks 24 through a pair of gaskets 47 and 48 having a structure as indicated in Fig. 6. These gaskets provide not only an airtight slip joint connection for the valve casing, but being of live rubber serve as a means to prevent metallic sounds from the instrument. The diameters of the nipples 37 and 46' may have any suitable relation to each other, but the effective bore of the nipple 46 is minute in-comparison with the other. A wall 49 extends across the nipple 46 and is provided with a minute pinhole 5O constituting the onl connection between the main bore 45 and the bore of the nipple. As heretofore, th tracker bar is provided with ports 51 each having an individual tube 52 for communication through a flexible pipe 53 with one of the valve casings. As shown best, however, in Fig. ,5, 1 provide a novel form of coupling between the tube 53 and the pipe 46, said coupling comprising a rubber sleeve 54 having an airtight sliip connection with the ends of the pipe an having a fine mesh wire screen 55 extending across the interior thereof serving to prevent any articles of lint, dust or the like from being conveyed from the tracker bar into the valve mechanism. The sleeve 54 is preferably embraced by a metal sheath 56 to give it stabilityf Under the usual conditions a great deal of trouble and expense are occasioned by the introduction of small particles of lint or paper from the music sheet into the valve mechanism. The screens 55 prevent such troubles, and since the several connecting joints are all of an easy slip nature, the screens.55 may be readily disconnected when necessary for blowing out the accumulated dust. I

With the parts formed and assembled as shown herein and described, upon operation of the bellows pump 19, a certain amount of negative air pressure is established uniformly in all parts of all of the air trunks 24. The air ports 51 of the tracker bar being normally closed by the music sheet passing thereover, there is no action of air through the pipe 45 and 53. The suction or reduced pressure through the nipples 37 and 46' establishes equilibriumon both sides of the diaphragm 36 and hence the weight of the valve 33 and the atmospheric pressure above it hold the valve seated upon the valve seat 34 preventing the reduced pressure from collapsing the pneumatics. When, however, a perforation of the music sheet registers with one of the ports 51 air is admitted at normal pressure valve mechanism is connected will cause the connected pneumatic to collapse due to the exhaustion of the air from such pneumatic through the pipes 20 and 23 downwardly through the ports 35 and outwardly through the nipple 37. When the paper again seals the port 51, equilibrium is quickly established again on both sides of the diaphragm as above described, allowing the valve 33 to drop by gravity, opening the upper valve seat 32 and closing upon the seat 34, when atmospheric air rushes downwardly throughthe ports 31 and pipes 23 and 20 allowing the movable portions of the pneumatics drop'freely ,by gravity.

I claim:

1. The herein described valve mechanism for pneumatic actions for musical instruments the same comprising a casing having J flanged base and top portions, the flanges being internally threaded and in alinement with each other, a valve drum fitted within the casing and having an exteriorthreaded surface serving to connect the two parts of the casing, a flexible diaphragm between the .base and the drum,.a reciprocating valve be-- tween the drum and the upper portion of thecasing, and a series of three connecting nipples extending in the same direction from one side of the valve mechanism, one from the base, one from the upper portion of the casing opposite the valve and the other intermediate thereof opposite .the drum.

2. The herein described musical instrument comprising a series of pneumatics, a tracker board, and a series of tubes leading from the tracker board to the several pneumatics, each of said tubes having a slip joint coupling device comprising a rubber The reduced pressure within the air trunk to which the particular sleeve having direct frictional connection with the tube sections, a dust collector within the rubber sleeve and held in place thereby, alnd a metallic sheath embracing the rubber s eeve.

3. In pneumatic action for musical instruments, a valve casing comprisin a main upper portion and a base, a va ve drum within the casing and serving to connect said main parts, the top of the casing and the top of the drum having spaced-openings, a valve adapted to reciprocate in said space between the openings and serving to close one or the other thereof, a flexible diaphragm secured between the lower end of the drum and said base, the base having an air port communicating with the bottoln of the diaphragm, and a stem extending from the valve into cooperation with the diaphragm.

4. The herein described valve mechanism for pneumatic actions, the same comprising a casing having a horizontal base with an upwardly projecting internally threaded flange, said base having a central air port therethrough, the upper portion of the easing comprising a cap whose lower portion is internally threaded and registers with the base flange, the top of the cap having an airport therethrough, a drum having an external screw thread fitted within the easing and serving to secure the base and casing top together through said screw threads, the top of the drum having an air port therethrough below the casing top air port, the bottom of the drum being open, a diaphragm held in place between the bottom edge of the drum and the base, a valve in the space between the top of the casing and the top of the drum and adapted to reciprocate between the air ports therein, said valve including a stem projecting into con: tact with the diaphragm, and a nipple tapped through the side of the casing and the side of the drum, serving to lock the casing and drum from relative rotation.

Witnesses:

EDWARD LEONARD, ELLA J. LEONARD.

JOSEPH rosrrsm 

